Multistable wake deflection amplifier

ABSTRACT

A fluidic amplifier for use in the performance of logical functions in digital systems utilizing a cylindrical or other shape obstruction in a power stream to produce a deflectable wake when the stream is a jet of approximately the same size as the deflecting shape.

United States Patent Auger 1 Feb. 22, 1972 [54] MULTISTABLE WAKE DEFLECTION 3,181,545 5/1965 Murphy, Jr. .Q ..137/8l.5 AMPLIFIER 3,209,775 10/1965 Dexter et al.. ..137/8 1.5 3,272,214 9/1966 Warren ..137/8 1 .5 Inventor: Raymond Auger, 456 Riverside Drive. 3,447,553 6/1969 Campagnuolo et al.. ..137/s1.5 New 10027 3,276,463 10/1966 Bowles ..137/81.5 3,495,253 2/1970 Richards... ..l37/81.5 [22] Sept 3,509,775 5/1970 Evans ..137/s1.5 x [21] App1.No.: 855,945

Primary Examiner-Samuel Scott [52 us. c1 ..l37/608, 137/81.5 Mame) Smythe Moor-e [51] Int. Cl. ..F15c 3/00 57 ABSTRACT [58] Field 01 Search ..137/81.5, 608,1

A fluidic amplifier for use in the performance of logical func- [56] References Cited tions in digital systems utilizing a cylindrical or other shape obstruction in a power stream to produce a deflectable wake UNITED STATES PATENTS when the stream is a jet of approximately the same size as the deflecting shape. 3,454,023 7/1969 Burke et a1 ..137/81.5 X 3,171,422 3/ 1965 Evans ..137/81.5 9 Claims, 8 Drawing Figures PATENTEDFEB 22 I972 sum 1 or 3 F|G.Ic

ATTORN EYS PATENTEDFEBZZ I972 3. 643 693 SHEET 3 BF 3 STAGE? STAGE. 2

INV N OR Kan/0M0 Hana ATTORNEY-S qyw lym MULTISTABLE WAKE DEFLECTION AMPLIFIER This invention relates to a method and means for a fluid amplifier and especially one which may be used, for example, for the performance of logical functions in digital systems.

Each of the different types of fluidic amplifiers presently in use hasunique advantages and disadvantages. One of the best known types of fluidic amplifiers is described by R. E. Bowles et al. in U.S. Pat. No. 3,396,619, and other patents. Amplifiers of this type deflect a power stream from one surface to another by changing the flow condition in the boundary layer with which the control port connects. The proper performance of this type of structure requires that the control ports be at subatmospheric pressure. If more than one control signal is required to operate a boundary layer device, it is difficult to isolate the signal in one passage from the other passages. Efforts to accomplish signal isolation have been achieved only with substantial loss in the gain of the amplifier. This is because signal isolation arrangements for this type of amplifier usually employ structures which attenuate a significant portion of the signals energy. The turbulence amplifier in U.S. Pat. No. 3,234,955 does not have the signal isolation problem, as the control nozzles for the amplifier are outside of any boundary layer effects, but said amplifier does have other problems for some uses. For example, it can be readily manufactured to produce only the NOR function, and the fact that its output pressure is limited to a fraction of pound per square inch (p.s.i.).

One of the objects of the present invention is to provide a fluidic amplifier construction and device which may be built as a low-pressure OR/NOR device, flip-flop device, for other unique logic structures, and may be built to operate without output pressures of many p.s.i.

Another of the objects of the invention is to provide a fluid amplifier having completely isolated independent inputs.

The fluid dynamic phenomenon utilized by the amplifier of the present invention does not appear to be treated in published studies, and appears to be unknown in the fields of fluid dynamics and fluidics. A well-known area of fluid dynamic analysis relates to the wakes of objects in streams, or the wakes of objects moving in a quiet liquid, particularly cylinders. The work of Theodore von Karman in analyzing the wakes of cylindrical objects in streams is well known and mentioned in basic fluid dynamic texts. Absent from the literature, however, is the case where the stream is a jet of approximately the same size as the cylinder or wake-deflecting device.

In one aspect of the invention, a fluid supply power stream nozzle is spaced from a wake deflector element and with the stream axis aligned with the axis thereof or at a predetermined position relative thereto. Preferably, the deflector is cylindrical but may take other shapes to produce a wake. The effective axis of the deflector is transversely across the power stream and the deflector is spaced from the nozzle. The power stream can be shifted axially relative to the effective axis of the deflector by a fluid jet or by movement of the deflector. Other aspects of the invention will become apparent from the description hereafter.

Other objects, advantages and features of the invention will become apparent from the following description and drawings which are merely exemplary.

In the drawings:

FIGS. la to 1d, inclusive, are schematic views of four conditions which may occur in connection with a jet stream of approximately the same size as a cylindrical deflector;

FIG. 2 is a schematic view of a flip-flop device embodying the invention;

FIG. 3 is a view similar to FIG. 2, partly in section, of a flipflop with inhibitable inputs;

FIG. 4 is a schematic view showing a counter circuit; and

FIG. 5 is a schematic view of a still further embodiment of the invention.

cylinder 11 and spaced therefrom by distance m, showing flow lines 12 and wake after the cylinder when the pressure of the jet stream is above a certain level or when the cylinder is close to the nozzle.

In FIG. 1b, the distance between the nozzle 10 and cylinder 1 l is increased to m+l. In this case, the flow after the cylinder can take only the two paths l3 and 14 with an angle between them of approximately. 60, as illustrated. When the nozzle is directed exactly at the center of the cylinder, the flow after the cylinder can be switched from path I4 to path 13 and back to 14 by the application of a low-velocity stream perpendicular or angularly disposed relative to the power stream 15 between nozzle 10 and cylinder 11. A control stream (not shown in FIG. lb) deflects power stream 15 a very small amount in order to accomplish the change in direction of the stream wake downstream of the cylinder deflector 11. If the cylinder is moved from a true central position relative to the axis of the power stream, for example, a few thousandths of an inch in the case of a 0.020-inch-diameter cylinder, this will be sufficient to switch the wake of the stream from one path to another such as indicated at 13 and 14in FIG. 1b.

One explanation of the phenomenon shown in FIG. 1b is as follows. When the distance between nozzle 10 and cylinder 11 is increased sufficiently, one of the two streams 12 of FIG. la continues to be deflected laterally, while the other stream attaches itself to the cylinder because of the Coanda effect so as to follow the cylinder to a separation point 16 as indicated in FIG. lb which is approximately 30 from the centerline of the power stream 15. To obtain a better understanding of why one-half of the stream separates immediately from the cylinder while the other one-half attaches to it, reference to FIG. 10 may be of assistance. Presuming that the same supply pressure for the power stream is emitting from nozzle I0 as in FIGS. 1a and 1b, it is seen that the greater distance m+2 between cylinder 11 and nozzle 10 (FIG. 1c) causes wake 17 to have three alternate paths 18, 19 and 20, each approximately 30 from the next adjacent path. When the wake is in direction 18 or 19, the phenomenon is identical to FIG. lb. However, there is also a center wake path 20 for the arrangement in FIG. c as stated. The three alternate wake paths can be obtained either by small movements of the cylinder 11 laterally from the centerline of the power stream 15 or by deflections of the power stream by an external control jet (not 'shown) operating at right angles thereto. As in FIG. lb, once established, the wake direction does not require continuous deflection of the power stream. The phenomenon in FIG. 10 is tristable and allows the construction of a tristable memory device. When the wake 17 after the cylinder 11 is in the center path 20, the stream on both sides of the cylinder 1 l attaches to it because of the Coanda effect previously mentioned.

FIG. 1d illustrates a still greater distance m+3 between nozzle l0 and cylinder 11, and indicates that the wake after the cylinder is now monostable and will follow a direction through the range of the angle K, in practice approximately 60. Control of wake 21 within this range will be related to offset 22 between the centerline of the power stream 15 and the center axis of the cylinder 11.

The early separation of streams on each side of a cylinder, FIG. la, can be explained in terms of Reynolds number and stream laminarity. The attachment of the streams to cylinder 11 (FIG. 1d) can be explained to be a result of a higher Reynolds number and stream turbulence. The situation described in prior literature places the cylinder in a wide uniform stream rather than a narrow jet stream approximating the size of the cylinder. In the latter case, the early separation configuration of FIG. 1a occurs at higher supply pressures than for the condition of much later separation from the cylinder shown in FIG. 1d. This is the reverse of the phenomenon encountered in a wide uniform stream but may be explained in terms of Mach number. The exact velocity of air emitting from small nozzles can approach supersonic velocities with relatively low flow consumption and at pressures well under 50 p.s.i. The shock wave produced by cylinder 11 may be the reason for the early separation of the streams in FIG. 1a. The same effect occurs at low supply pressures and stream velocities, but because of laminar flow. In the case of laminar flow around the cylinder, the divided or split wake will reform into a single wake because of entrainment only a few cylinder diameters downstream. In the case of turbulent split wakes (FIG. la), reformation into a single wake is incomplete and occurs or 20 cylinder diameters, or more, downstream from the cylinder. In the case of deflected wakes (FIGS. lb and 1c), reformation into a single wake occurs approximately 1.5 to 2 cylinder diameters downstream.

The multistable states of the wake, FIGS. lb and It, may be further explained. The tendency of the split stream to separate from the cylinder shortly after impact as in FIG. la occurs at high stream velocities. If the stream does not immediately separate from the cylinder, but remains attached because of the Coanda effect, it quickly loses velocity until a surface layer of laminar flow develops and the stream becomes detached from the cylinder. For a relatively narrow range of stream velocities, each half of the divided stream may follow either route with equal stability, immediate separation or attachment to the cylinder for approximately 90 around its circumference. For a somewhat lower jet velocity, while stream deflection from the cylinder may occur immediately, the more stable state for the stream is for it to be attached to the cylinder, in which case the tristability of FIG. 1c will occur. With low supply jet velocity, the tendency of the stream to detach from the cylinder on contact is very weak, consequently both streams will attach, as in FIG. 1d, and remain attached no matter what portion of the main stream passes on one side of the cylinder or the other. In FIG. 1b, the side of the stream which detaches first, the right-hand side as shown, is that which contains the major portion of the power stream 15. That is to say, as the center of the power stream containing the highest velocity strikes the cylinder 11, its tendency is to immediately detach.

The occurrence of the phenomenon in FIGS. lb and 10 requires the choice of the correct nozzle diameter, cylinder diameter, cylinder-to-nozzle distance and supply pressure. In the case of very small cylinders, e.g., under 0.015 inch in diameter, the phenomenon will occur at two widely separated supply pressures, the higher one in the 20 to 30 p.s.i. range, and the lower one in the it-p.s.i. range. The cylinder diameter is approximately one to two times the nozzle diameter, depending on the nozzle to cylinder distance, the greater distance requiring a larger cylinder. The determination of the ideal relationship between the above factors may be experimentally established for particular uses. One set of factors will make the phenomenon shown in FIG. 1b quite stable, while another set offactors will make it very easily disturbed. A relatively sensitive relationship may be obtained with a cylinder of 0.032 inch diameter, a nozzle of 0.032 inch bore diameter, and a distance between them of 0.1 inch. The bistable deflected wake of FIG. lb will be observed at supply pressures ranging from 3 to 7 p.s.i.

It is possible to locate the control jets at a considerable distance from the supply nozzle and cylinder. This enables a number of control jets to be grouped adjacent to one another so that multiple input flip-flop configurations and NOR configurations can be constructed. FIG. 2 illustrates a flip-flop having three inputs 23 and 24 on each side. As the flow from the input ports may be laminar, it can transverse a considerable distance without substantial energy loss. The inputs 23 and 24 are the controls while the supply stream comes from the nozzle 10, as described in connection with the cylinder 11, outputs being indicated at 25 and 26.

A second possible arrangement, due to the considerable distance which may exist between a control jet and a power stream, is shown in FIG. 3. The FIG. 3. configuration indicates use of laminar techniques, so that all of the passages shown are rectangular in cross section. The circular ports designated V are vents to atmosphere or to a reference pressure. The supply or power jet is designated S, and the outputs are shown at O and O Inhibitionary inputs Inl and In2 are directed toward their adjacent vents so that any flows from regular inputs l and I will be deflected by the inhibitionary inputs toward the vents and away from the power stream from the supply nozzle S. A flip-flow with inhibitable inputs greatly facilitates the construction of countercircuits and shift registers.

FIG. 4 shows a counter circuit utilizing such elements and the operation of this circuit can be described as follows. The element 27 is a single-input OR/NOR device. A positive signal into the port 28 produces a positive pressure from port 29. The removal of the signal produces a pressure at port 30. The port 31 is the supply port. The connection to a supply pressure manifold can be connected to ports 31, 32, 33, 34 and 35. The element 27 may not be required in many practical instances because the source of signals for operation of the counter may be available in complementary form. Flip-flop elements 32 and 33 (FIG. 4) form the first stage of the counter circuit. The outputs of element 27 cause the regular inputs of elements 32 and 33, namely inputs 36 and 37, to be inhibited alternately. Elements 32 and 33 are connected so that the output state of element 32 will alter the state of element 33 which will in turn alter the state of element 32. Without inhibitionary signals, elements 32 and 33 are connected to form a type of oscillator. The alternate energizing of the inhibitionary ports 38, 39 and 38', 39' of each flip-flop allows its state to be changed with each change of element 27. Pressurizing of port 28 removes pressure from port 30 and ports 38' and 39. This allows element 33 to change state. The removal of pressure from port 28 removes pressure from port 29 and from 38 and 39. This allows element 32 to change state. The output of element 33 acts as the inputs to the inhibiting jets of elements 34 and 35. Additional inputs can be added to each flip-flop to enable it to be reset to a standard state at the start of a count sequence.

To construct a shift register utilizing inhibitable flip-flop devices, a chain of flip-flops can be used, the inputs of each being connected to the outputs of the previous flip-flop. All of the odd-numbered flip-flop devices can have their inhibition inputs connected to one line, and all of the even-numbered flip-flop devices can have their inhibition inputs connected to another line. Alternately, depressurizing and repressuring the two inhibition lines to which all of the flip-flop devices are connected will produce a change of state in the first of the chain of flip-flop devices to be transmitted down the length of the chain, one flip-flop at a time.

The construction of OR/NOR elements utilizing the deflected wake effect is accomplished by locating cylinder 11 off of the centerline of the power jet. This will cause the wake to be normally deflected approximately 30 from the center line of the power jet. A control jet, which deflects the power stream sufficiently to cause its centerline to cross the center line of the cylinder 11, will cause the wake to deflect 60. Removal of the control signal or jet will cause the wake to return to its original location. Should there be a need for greater pressure or power gain than is obtainable in a single stage of this type of amplifier, it is possible to directly interact the wake of one cylinder into the power jet of a second cylinder as depicted in FIG. 5.

FIG. 5 shows a supply nozzle 40 producing a power stream 41 impinging on a first cylinder 42. Wake 43 is deflected by control jet 44 from input nozzle 45. Deflected wake 43 strikes the power jet or stream 46 issuing from supply nozzle 47, deflecting its wake toward and into the output element 48, there being an intervening second cylinder 49, as shown. Removal of pressure from control nozzle 45 causes the wake 43 of power stream 41 to follow the path 50 which, in turn, allows the wake 51 of power stream 46 to enter output element 52. In a similar manner, more stages can be added to this arrangement depending upon application and requirements.

Shapes other than true cylinders may be used to produce wakes which will behave substantially as those described herein. No simple geometric limits can be placed on the range of shapes which will produce deflected wakes. Shapes having cross sections such as triangles, octagons, hexagons and squares may be used.

It will be understood that various details of construction and arrangement of parts may be made without departing from the spirit of the invention.

What is claimed is:

1. In a fluidic circuit device, the combination including a fluid supply nozzle element producing a power stream, a cylindrical wake deflector means in the path of and approximately the width of said power stream, the axis of the deflector being substantially normal to the power stream, and means for changing the axis of said power stream relative to said deflector so that a small shifting of the deflector relative to the axis of the power stream will deflect the wake downstream from the cylindrical deflector, said deflector being spaced a sufficient distance from said supply nozzle to effect a splitting and recombining of the power stream into a single wake.

2. A device as claimed in claim 1 wherein there is a fluid control nozzle directed at the power stream between said fluid supply nozzle element and said wake deflector.

3. A device as claimed in claim 1 wherein said wake defle'ctor means is movable transversely relative to the axis of the power stream to cause angular deflection of said wake.

4. A device as claimed in claim 1 wherein said cylindrical wake deflector means is spaced a sufficient distance from the outlet of said supply nozzle element to cause the deflected wake to be bistable along two angular paths.

5. A device as claimed in claim 1 wherein said cylindrical wake deflector means is spaced a sufficient distance from the outlet of said supply nozzle element to cause the deflected wake to be tristable along three paths.

6. In a fluidic circuit apparatus, the combination comprising a power stream fluid supply nozzle element having a power stream bore, a shiftable cylindrical wake deflector means downstream from said nozzle with its axis substantially perpendicular to the axis of said nozzle element and the power stream produced thereby, the cylindrical wake deflector means having a diameter approximating the diameter of the noule bore and the width of the power stream, plural outlet conduit elements downstream from the wake deflector means, and having angularly divergent axes, and plural convergent axis control nozzles on opposite sides of the power stream nozzle element and cylindrical deflector means, said control nozzles producing selectively energizable control streams which impinge upon the power stream from the power stream nozzle element between the power stream nozzle and said cylinder and deflect the wake downstream of the cylinder.

7. An apparatus as claimed in claim 6 wherein said plural outlet conduit elements comprise a pair of elements whose flow axes intersect substantially on the axis of the wake deflector means and the axis of the power stream.

8. An apparatus as claimed in claim 6 wherein said convergent axis control nozzles comprise at least three control nozzles on opposite sides of the power stream.

9. In a fluidic circuit apparatus, the combination including a first cylindrical power stream wake deflector, a first power stream nozzle spaced from said first deflector, a control nozzle between the first power stream nozzle and deflector for producing a control jet substantially at right angles to the power stream emitted from the first power stream nozzle, 21 second cylindrical power stream deflector spaced laterally of the first deflector, a second power stream nozzle downstream from the first power stream nozzle and first deflector and disposed at an angle to the power stream axis of the first power stream nozzle, the second power stream nozzle producing a second power stream directed toward the second cylindrical wake deflector, and at least a pair of spaced deflected wake outlet conduit elements spaced from the second deflector, whereby said control jet may be utilized to deflect the wake of the power stream from the first power stream nozzle into the power stream from the second power stream nozzle and the latter power stream may have its wake deflected selectively into either outlet conduit element. 

1. In a fluidic circuit device, the combination including a fluid supply nozzle element producing a power stream, a cylindrical wake deflector means in the path of and approximately the width of said power stream, the axis of the deflector being substantially normal to the power stream, and means for changing the axis of said power stream relative to said deflector so that a small shifting of the deflector relative to the axis of the power stream will deflect the wake downstream from the cylindrical deflector, said deflector being spaced a sufficient distance from said supply nozzle to effect a splitting and recombining of the power stream into a single wake.
 2. A device as claimed in claim 1 wherein there is a fluid control nozzle directed at the power stream between said fluid supply nozzle element and said wake deflector.
 3. A device as claimed in claim 1 wherein said wake deflector means is movable transversely relative to the axis of the power Stream to cause angular deflection of said wake.
 4. A device as claimed in claim 1 wherein said cylindrical wake deflector means is spaced a sufficient distance from the outlet of said supply nozzle element to cause the deflected wake to be bistable along two angular paths.
 5. A device as claimed in claim 1 wherein said cylindrical wake deflector means is spaced a sufficient distance from the outlet of said supply nozzle element to cause the deflected wake to be tristable along three paths.
 6. In a fluidic circuit apparatus, the combination comprising a power stream fluid supply nozzle element having a power stream bore, a shiftable cylindrical wake deflector means downstream from said nozzle with its axis substantially perpendicular to the axis of said nozzle element and the power stream produced thereby, the cylindrical wake deflector means having a diameter approximating the diameter of the nozzle bore and the width of the power stream, plural outlet conduit elements downstream from the wake deflector means, and having angularly divergent axes, and plural convergent axis control nozzles on opposite sides of the power stream nozzle element and cylindrical deflector means, said control nozzles producing selectively energizable control streams which impinge upon the power stream from the power stream nozzle element between the power stream nozzle and said cylinder and deflect the wake downstream of the cylinder.
 7. An apparatus as claimed in claim 6 wherein said plural outlet conduit elements comprise a pair of elements whose flow axes intersect substantially on the axis of the wake deflector means and the axis of the power stream.
 8. An apparatus as claimed in claim 6 wherein said convergent axis control nozzles comprise at least three control nozzles on opposite sides of the power stream.
 9. In a fluidic circuit apparatus, the combination including a first cylindrical power stream wake deflector, a first power stream nozzle spaced from said first deflector, a control nozzle between the first power stream nozzle and deflector for producing a control jet substantially at right angles to the power stream emitted from the first power stream nozzle, a second cylindrical power stream deflector spaced laterally of the first deflector, a second power stream nozzle downstream from the first power stream nozzle and first deflector and disposed at an angle to the power stream axis of the first power stream nozzle, the second power stream nozzle producing a second power stream directed toward the second cylindrical wake deflector, and at least a pair of spaced deflected wake outlet conduit elements spaced from the second deflector, whereby said control jet may be utilized to deflect the wake of the power stream from the first power stream nozzle into the power stream from the second power stream nozzle and the latter power stream may have its wake deflected selectively into either outlet conduit element. 